Subject: Re: Perception as memory / models of pitch From: Martin Braun <nombraun@xxxxxxxx> Date: Wed, 2 Sep 2009 18:48:30 +0200 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Dear Eric and list, "1) I'd be grateful if you could clarify my thoughts...... (How) does it necessarily follow that categorization must be coupled as an integral part of this temporal pitch extraction process?? My understanding is that it likely occurs at a different location e.g. language areas (?)" Neither the assumed prelinguistic categorization in the thalamus (see our 2005 paper), nor the linguistic one in the neocortex are parts of the periodicity analysis. This occurs, according to all data that we have, in the inferior colliculus, i.e. the nucleus that almost exclusively delivers all ascending auditory input into the thalamus. The periodicity filters in the midbrain, e.g. formed by tuned neuronal membrane time constants, are vulnerable to slight biochemical detuning. "3) Another question, how stable must a neural reference (?pacemaker) be to equal the known stability of AP normally (<50 cents) ? Does such a pacemaker exist for all phase-locking frequencies or even just spanning an octave?" The verbal categories "C", "C#", "D", etc are stable within ca +/- 50 Cent. The periodicity detectors in the midbrain probably do not categorize very much. We have APers who can reply things like "D, but 20 Cent sharp". Martin --------------------------------------------------------------------- Martin Braun Neuroscience of Music S-671 95 Klässbol Sweden web site: http://w1.570.telia.com/~u57011259/index.htm ----- Original Message ----- From: "Eric LePage" <ericlepage@xxxxxxxx> To: <AUDITORY@xxxxxxxx> Sent: Wednesday, September 02, 2009 11:01 AM Subject: Re: Perception as memory / models of pitch Dear Martin and list, Thanks for the reminder. When you first reported the carbamazepine effect, I was fully prepared to try it myself, but a veterinarian friend talked me out of it! 1) I'd be grateful if you could clarify my thoughts......